Morphological and molecular discrimination of green macroalgae Chaetomorpha aerea and C. linum  

作　　者：HUANG Bingxin TENG Linhong DING Lanping 

机构地区：[1]Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Sciences, Tianjin Normal University, Tianjin 300387, China [2]Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China [3]Graduate University of Chinese Academy of Sciences, Beijing 100049, China [4]Marine Biology Institute, Shantou University, Shantou 515063, China

出　　处：《Acta Oceanologica Sinica》2016年第4期118-123,共6页海洋学报（英文版）

基　　金：The National Key Technology R&D Program of China under contract No.2012BAC07B05;the National Natural Science Foundation of China under contract Nos 31400186,31270257 and 31093440;the Science and Technology Plan Project of Guangdong Province under contract No.2012A020200007;the Science and Technology Plan Project of Shantou City,China under contract No.2012–171

摘　　要：Green macroalgae Chaetomorpha aerea and C. linum are taxonomically confused. In this paper, we tried morphological and molecular analyses to separate these two species. C. aerea and C. linum can be distinguished from morphological characteritics, such as frond dimension, cells size and shape, their mean length/width ratios（LWR）, and cell walls constriction. Thalli of C. aerea attenuate basipetally, with diameter 270–500 μm at upper portion, 160–360 μm at middle portion, 100–160 μm at basal portion. For the upper part, the length of cells is less than their diameter. Cell walls usually constrict at the dissepiments, which are pellucid or colorless and give the filament beaded appearance. In contrast, thalli of C. linum often have a constant diameter of 90–300 μm within the same individual, cell walls usually do not constrict and cells are cylindrical or barrel shaped. The LWR is larger than that of C. aerea. Results show that the pairwise distance between two species is 3.6%–3.7% for 18 S r RNA gene and 53.5%–54.3% for ITS region. In phylogeny, they distribute at distant clades, which confirms a genetic divergence at molecular level. In addition, morphological data indicates that filament diameter of C. linum samples is highly variable, ranging from 90 μm to 300 μm. Then these two species can be considered as separate species.Green macroalgae Chaetomorpha aerea and C. linum are taxonomically confused. In this paper, we tried morphological and molecular analyses to separate these two species. C. aerea and C. linum can be distinguished from morphological characteritics, such as frond dimension, cells size and shape, their mean length/width ratios（LWR）, and cell walls constriction. Thalli of C. aerea attenuate basipetally, with diameter 270–500 μm at upper portion, 160–360 μm at middle portion, 100–160 μm at basal portion. For the upper part, the length of cells is less than their diameter. Cell walls usually constrict at the dissepiments, which are pellucid or colorless and give the filament beaded appearance. In contrast, thalli of C. linum often have a constant diameter of 90–300 μm within the same individual, cell walls usually do not constrict and cells are cylindrical or barrel shaped. The LWR is larger than that of C. aerea. Results show that the pairwise distance between two species is 3.6%–3.7% for 18 S r RNA gene and 53.5%–54.3% for ITS region. In phylogeny, they distribute at distant clades, which confirms a genetic divergence at molecular level. In addition, morphological data indicates that filament diameter of C. linum samples is highly variable, ranging from 90 μm to 300 μm. Then these two species can be considered as separate species.

关 键 词：Chaetomorpha aerea Chaetomorpha linum molecular identification morphology comparison 18S rRNA ITS 

分 类 号：Q949.2[生物学—植物学]